CN104018790A - Roadway rock burst early-warning method based on rock noise monitoring - Google Patents

Abstract

The invention relates to a roadway rock burst early-warning method based on rock noise monitoring. The method comprises the steps that two rock noise probes are arranged at the interval ranging from 100 m to 150 m in an area with potential burst risks, the distance between the first probe and a stope working face end or a driving working face head-on part is larger than or equal to 30 m, and the two probes alternately move forwards along with the pushing of the working face; whether probe installation and probe noise insulation are qualified or not is detected; rock noise activities are monitored in real time; the energy and frequency monitored by the probe with the lower voice frequency is selected as the rock noise activity energy and the frequency value of the monitored area; whether the working face is in the production period or not is determined; hour or shift shock noise energy and frequency abnormal coefficients in the production period or the non-production period are obtained through calculation; the index value with the larger abnormal coefficient is selected for burst risk evaluation. The roadway rock burst early-warning method based on rock noise monitoring plays a positive role in promoting the development of rock burst prediction and forecast and prevention and treatment technology, and is significant in technical, economic and security benefits.

Description

Press method for early warning roadway bump based on monitoring ground sound

Technical field

The present invention relates to a kind of method that coal mine roadway shock hazard is evaluated, be specially a kind of roadway bump based on monitoring ground sound and press method for early warning, the evaluation of rock blast hazard mine laneway shock hazard and bump short-term, imminent earthquake early warning are mainly used in, for instructing the solution danger of coal mine roadway bump and withdrawing relevant personnel and equipment.

Background technology

Bump is one of major casualty of facing of deep coalmining, and according to incompletely statistics, during 2000～2012,304 of bump accidents occur altogether in national colliery, the number of casualties 509 people.Along with the continuous increase of the coal mining degree of depth, rock blast hazard and a series of accidents of causing thus also become more and more serious and general as gas, gushing water and ore deposit shake etc.Only have the reliable monitoring and the forecast that realize impact danger, and then get rid of accident potential, could improve production security under coal mine, reduce to greatest extent casualties and property loss.

At present domestic based on field monitoring impact compress into row prediction method mainly contain electromagnetic radiation method, stress in coal bed method, rock noise method, micro-seismic method and drilling cuttings method.Drilling cuttings method is the most original means, has space-time discontinuity, and workload is large, and data are unreliable, and predictablity rate is low; What micro-seismic method was monitored is high-octane coal petrography Surface Rupture Events, can only be applied to the judgement of bump risk zontation and medium-term and long-term danger of burst trend, and can not realize short-term early warning; Although the continuous and instant early warning that stress in coal bed monitoring and electromagnetic radiation monitoring can be realized impact and press, stress in coal bed monitoring belongs to a monitoring, and scope is less, and coal petrography stress state is not the adequate condition that determines that bump occurs; Electromagnetic radiation mainly carrys out monitoring and prediction bump according to country rock electromagnetic radiation intensity, but the various signals of telecommunication in down-hole often produce very large interference to monitored data, easily causes the uncertainty of result.Compared with said method, the advantage of rock noise method is that monitoring range is large, and precursor information enriches and is difficult for being disturbed, and these means can provide the important precursor information of bump.By monitoring ground sound system, real-time dynamic monitoring is carried out in potential the rock burst fatalness area, can obtain the multidate information that the Emergence and Development in front coal petrography crack occurs bump, a series of rock noise parameters such as rock noise event, energy release rate, time delay are provided according to monitoring system, find out rock noise mechanics, judge rock mass stress and destruction process with this, evaluate the stability of rock mass, and then judge the danger of burst grade of monitored area.Monitoring ground sound is one of technological means most advanced and the most promising in current bump short-term, imminent earthquake early warning technology.

But, at present domestic to the Prediction of Rock Burst prediction research based on monitoring ground sound also in the stage of fumbling, also shortcoming very of the researchs such as rock noise Precursory Characters, shock hazard evaluation theory, criterion and warning index is pressed on impact ground.How to set up rock noise and evaluate foundation and the criterion of shock hazard, it is the key that realizes bump short-term, imminent earthquake early warning that How to choose has prediction significance and sensitive index definite early warning index.

Summary of the invention

Current Prediction of Rock Burst forecasts that particularly short-term early warning is a global problem in rock mechanics field, and domestic current research work in this respect also belongs to experimental, prediction qualitatively mostly, and operability is not high.At present, more research has been carried out in the Prediction of Rock Burst forecast based on electromagnetic radiation monitoring, stress in coal bed monitoring, but success rate prediction need to improve.Monitoring ground sound is aspect bump monitoring and forecast, to develop technology faster in recent years, progressively become one of Main Means of coal mine rock burst real-time dynamic monitoring, rational evaluation and the reliable early warning of carrying out shock hazard based on monitoring ground sound result are current problems in the urgent need to address, are also important breakthrough mouths that improves China's bump research work level.

The object of this invention is to provide a kind of new method for the evaluation of coal mine roadway shock hazard and Prediction of Rock Burst forecast.Because monitoring ground sound has the feature of Real-Time Monitoring, and can obtain in the 300m radius of monitored area the coal petrography information of breaking, therefore monitoring information has continuity and scope is wide, and the analysis based on monitored data can directly reflect coal petrography stress destruction state, is subject to external interference little.

Press a method for early warning roadway bump based on monitoring ground sound, comprise the steps:

(1) arrange rock noise probe in the region with potential impact danger, two rock noise probes are arranged in each region, probe is arranged on anchor pole exposure site, two probe spacings are 100-150m, distance >=30m that first probe distance stope termination or driving face are met head on, along with the propelling of work plane, two probes alternately move forward;

(2) whether detection probe installation and probe sound insulation be qualified;

(3) Real-Time Monitoring that adopts monitoring ground sound system to carry out rock noise activity, system is added up energy and the frequency of each probe rock noise activity per minute automatically; In contrastive detection region two the rock noise frequencys that probe is per minute, choose probe that the rock noise frequency is lower and monitor energy and the frequency movable energy of rock noise and the frequency value as monitored area, place in this minute;

(4) determine that work plane belongs to production period (recovery time section) or non-productive period;

(5) calculate energy and the frequency of per hour or the activity of every order of classes or grades at school rock noise according to the movable energy of rock noise per minute in monitored area and the frequency, whether produce in conjunction with down-hole simultaneously, calculate respectively production period or non-productive period hour or class rock noise energy and the abnormal coefficient of the frequency;

(6) choose hour or class rock noise energy and the larger desired value of the abnormal coefficient of the frequency are carried out shock hazard evaluation.

In step (1), do not have the geology fracture area of disturbing elastic wave propagation between the infield of described probe and monitored area, described geology fracture area comprises work plane, tomography, goaf etc.

Described bolt diameter is described anchor pole gos deep into the length>=1.5m in coal and rock.

In step (2), detection probe installs whether qualified method is: on distance is popped one's head in other anchor poles of 5m-20m, knock with tup; If receive all test signals of knocking, the installation qualification of popping one's head in.

The whether qualified method of probe sound insulation that detection is arranged on anchor pole is: on other anchor poles of distance probe < 5m, knock with tup; If the noise within 5m can not be recorded, be arranged on probe sound insulation on anchor pole qualified.The weight of tup is 3.5kg.

In step (4), determine that work plane belongs to production period or the method for non-productive period is: pass through W _pparameter to working surface production during and non-productive period divide, W _tbe the average of this parameter in certain working time unit, work as W _p>aW _ttime this period be production period, a gets 0.2, W conventionally _pparameter is the numerical value of output, advance rate, coal-winning machine available machine time or power consumption.W _pthe quantity of (class or one hour) in certain hour, W _pand W _ttime is identical.

In step (5), the class of production period or non-productive period or hour rock noise energy and the abnormal coefficient of the frequency are following 8 desired values:

1) production period, the abnormal coefficient of class's rock noise frequency---k _azw

2) non-productive period, the abnormal coefficient of class's rock noise frequency---k _azn

3) production period, hour abnormal coefficient of the rock noise frequency---k _ahw

4) non-productive period, hour abnormal coefficient of the rock noise frequency---k _ahn

5) production period, the abnormal coefficient of class's rock noise energy---k _ezw

6) non-productive period, the abnormal coefficient of class's rock noise energy---k _ezn

7) production period, hour abnormal coefficient of rock noise energy---k _ehw

8) non-productive period, hour abnormal coefficient of rock noise energy---k _ehn

The computational methods of above-mentioned 8 desired values, with k _azwand k _ezwfor example, its computational process is as follows:

$k_{\mathrm{azw}}=|\frac{N_{\mathrm{azw}}-\stackrel{\&OverBar;}{N_{\mathrm{azw}}}*100\%}{N_{\mathrm{azw}}}*100\%|$

In formula:

N _azw: production period, the rock noise frequency value of current class;

the average of front 10 class's of production rock noise frequencys.

$k_{\mathrm{ezw}}=|\frac{E_{\mathrm{ezw}}-\stackrel{\&OverBar;}{E_{\mathrm{ezw}}}*100\%}{E_{\mathrm{ezw}}}*100\%|$

In formula:

E _ezw: production period, the rock noise energy value of current class;

the average of front 10 class's of production rock noise energy.

With reference to above-mentioned formula, can calculate successively other 6 desired values.

In step (6), the evaluation criterion of carrying out shock hazard evaluation is as shown in table 1.Divide four danger classess according to abnormal coefficient, without dangerous: <0.25, weak danger: 0.25-1.0, moderate risk: 1.0-2.0 is dangerous by force: >2.0.

Table 1 shock hazard evaluation table

If when a upper class finishes, in monitored area, danger of burst grade is a and b, this order of classes or grades at school only carries out a class danger classes evaluation, otherwise also need to calculate rock noise energy hourly and the abnormal coefficient of the frequency, and carry out a hour shock hazard evaluation according to table 1, take corresponding Preventing Countermeasures according to evaluation result.

By said method, realize the shock hazard of monitored area has been carried out to grading evaluation and short-term early warning.

Advantage of the present invention: rock noise method is the most promising technology in bump short-term forecast forecast, but the domestic research about rock noise evaluation and early warning technology is at present also substantially in space state.The method is to improving the monitoring ground sound system application level in China's bump mine, and to promoting Prediction of Rock Burst forecast and the development of Prevention Technique will play positive role, technology, economy, safety benefit are remarkable.

Below by detailed description of the invention, the present invention will be further described, but and do not mean that limiting the scope of the invention.

Brief description of the drawings

Fig. 1 is that in the inventive method, monitoring ground sound is arranged schematic diagram.

Detailed description of the invention

The present invention is based on monitoring ground sound roadway bump press method for early warning, concrete steps comprise:

I is arranged rock noise probe in the region with potential impact danger, must not have the geology fracture area (for example: work plane, tomography, goaf etc.) of disturbing elastic wave propagation between infield and monitored area.The rock noise probe quantity of arranging for each region is two, and probe should be arranged on anchor pole exposure site, the length that anchor pole gos deep in coal and rock must not be less than 1.5m, the height (expose height) that anchor pole exposes coal and rock is generally 20-30mm.Two probe spacings are 100-150m, and the distance that first probe distance stope termination or driving face are met head on must not be less than 30m.Along with the propelling of work plane, two probes alternately move forward.As shown in Figure 1, along with work plane constantly advances to probe, just this nearest probe should be moved on to another probe rear in the time that the distance of that nearest probe of work plane is less than 30m, two probes alternately move forward.

II is knocked on other anchor poles in (being no more than 20m) and 5m beyond distance probe 5m with the tup of heavy 3.5kg, if knock test signal beyond can receiving all 5m, the installation qualification of popping one's head in is described.If the noise within 5m can not be recorded, be arranged on probe sound insulation on anchor pole qualified.Generally swinging hammer is highly 0.3-0.5m.

III adopts ARES-5/E monitoring ground sound system, the Real-Time Monitoring that carries out rock noise activity, and system is added up energy and the frequency of each probe rock noise activity per minute automatically.In contrastive detection region two the rock noise frequencys that probe is per minute, choose probe that the rock noise frequency is lower and monitor energy and the frequency movable energy of rock noise and the frequency value as monitored area, place in this minute.

IV determines that whether work plane belongs to recovery time section, passes through W _pparameter (for example: output, advance rate, coal-winning machine available machine time, power consumption) to during working surface production and non-productive period divide, W _tthe average of unit intrinsic parameter of certain working time, W _p>aW _tcan think that this period is production period, a gets 0.2 conventionally.

W _pparameter can be chosen any one kind of them from the numerical value of output, advance rate, coal-winning machine available machine time and power consumption, W _pthe quantity of (class or one hour) in certain hour, W _tthe average of this parameter in certain working time unit, W _pand W _ttime is identical, such as W _tfor the average coal production of work plane per tour (being generally 8 hours), W _pfor the coal production of this class that will evaluate.

V can be calculated the frequency and the energy of the activity of per hour or every order of classes or grades at school rock noise according to the movable energy of rock noise per minute in above-mentioned monitored area and the frequency, whether produces in conjunction with down-hole simultaneously, by can be calculated following 8 desired values:

(1) production period, the abnormal coefficient of class's rock noise frequency---k _azw

(2) non-productive period, the abnormal coefficient of class's rock noise frequency---k _azn

(3) production period, hour abnormal coefficient of the rock noise frequency---k _ahw

(4) non-productive period, hour abnormal coefficient of the rock noise frequency---k _ahn

(5) production period, the abnormal coefficient of class's rock noise energy---k _ezw

(6) non-productive period, the abnormal coefficient of class's rock noise energy---k _ezn

(7) production period, hour abnormal coefficient of rock noise energy---k _ehw

(8) non-productive period, hour abnormal coefficient of rock noise energy---k _ehn

With k _azwand k _ezwfor example, its computational process is as follows:

$k_{\mathrm{azw}}=|\frac{N_{\mathrm{azw}}-\stackrel{\&OverBar;}{N_{\mathrm{azw}}}*100\%}{N_{\mathrm{azw}}}*100\%|$

$k_{\mathrm{ezw}}=|\frac{E_{\mathrm{ezw}}-\stackrel{\&OverBar;}{E_{\mathrm{ezw}}}*100\%}{E_{\mathrm{ezw}}}*100\%|$

In formula:

E _ezw, N _azw---production period, rock noise energy and the frequency value of current class;

---the average of front 10 class's of production rock noise energy and the frequency.

With reference to above-mentioned formula, can calculate successively other 6 desired values.

VI is chosen class's (or hour) energy and the larger desired value of the abnormal coefficient of the frequency is carried out shock hazard evaluation.Evaluate the precarious position of a class, this class is the class of production, and evaluating has two so, is respectively k _azwand k _ezw, produce the abnormal coefficient of the frequency between schedule and produce the abnormal coefficient of energy between schedule, can calculate and obtain respectively a value (being greater than 0) according to above-mentioned formula, the large value of getting in two numerical value is evaluated.

According to the evaluation criterion shown in table 1, divide 4 grades as shown in table 1 according to the size of desired value, each grade represents different precarious positions, a level is minimum, d level, for the highest, need to be formulated different Preventing Countermeasures according to different danger classess, to ensure safety in production.

If when a upper class finishes, in monitored area, danger of burst grade is a and b, this order of classes or grades at school only carries out a class danger classes evaluation, otherwise also need to calculate rock noise energy hourly and the abnormal coefficient of the frequency, and carry out a hour shock hazard evaluation according to table 1, take corresponding Preventing Countermeasures according to evaluation result.With regard to having realized, the shock hazard of monitored area is carried out to grading evaluation and short-term early warning like this.

Suppose that a certain stope need to carry out monitoring ground sound and Risk Assessments, rock noise arranges that schematic diagram is that shown in Fig. 1, work plane constantly moves forward, and monitoring ground sound region is 150-300m left and right, work plane front scope (dotted portion).

Current class, i.e. mornig shift one day (8:00-16:00), working surface production coal W _pbe 120 tons, the average coal production W of this work plane class _tit is 1000 tons, due to W _p<aW _t, can judge that this class is as nonproductive class.

According to rock noise monitoring result, rock noise total number of events (being the rock noise frequency) occurs for this class is 1500, and this class of rock noise cumlative energy is 100000J, and before this class, the rock noise frequency of 10 nonproductive classes and the average of energy are respectively 1000/class, 150000J:

$k_{\mathrm{azn}}=|\frac{N_{\mathrm{azn}}-\stackrel{\&OverBar;}{N_{\mathrm{azn}}}\&times;100\%}{N_{\mathrm{azn}}}\&times;100\%|=|\frac{1500-1000}{1000}\&times;100\%|=0.5$

$k_{\mathrm{ezn}}=|\frac{E_{\mathrm{ezn}}-\stackrel{\&OverBar;}{E_{\mathrm{ezn}}}\&times;100\%}{E_{\mathrm{ezn}}}\&times;100\%|=|\frac{100000-150000}{150000}\&times;100\%|=0.33$

In formula:

E _ezn, N _azn---non-productive period, rock noise energy and the frequency value of current class;

---the average of front 10 nonproductive class's rock noise energy and the frequency.

Due to: kazn>kezn is final evaluation index so get kazn, can judge that according to table 1 danger classes is now b level, weak dangerous, should take corresponding Preventing Countermeasures according to this grade.

Because the time interval that adopts order of classes or grades at school to carry out Risk Assessments is grown, (be a class circulation timei, be generally 8 hours), in the time that the danger classes of a upper class is c and d level, consider from guaranteeing security standpoint, Risk Assessments in this class of recovery process need to carry out taking hour as moving step length, evaluated a unsafe condition every one hour, evaluation method is identical with order of classes or grades at school.

Pass through the inventive method, adopt rock noise energy and the abnormal coefficient of the frequency to carry out shock hazard evaluation and the early warning of bump short-term, operability is high, can obtain rational evaluation and the reliable early warning of shock hazard, has improved China's bump research work level.

Claims (9)

1. press a method for early warning roadway bump based on monitoring ground sound, comprise the steps:

(1) arrange rock noise probe in the region with potential impact danger, two rock noise probes are arranged in each region, probe is arranged on anchor pole exposure site, two probe spacings are 100-150m, distance >=30m that first probe distance stope termination or driving face are met head on, along with the propelling of work plane, two probes alternately move forward;

(2) whether detection probe installation and probe sound insulation be qualified;

(3) Real-Time Monitoring that adopts monitoring ground sound system to carry out rock noise activity, system is added up energy and the frequency of each probe rock noise activity per minute automatically; In contrastive detection region two the rock noise frequencys that probe is per minute, choose probe that the rock noise frequency is lower and monitor energy and the frequency movable energy of rock noise and the frequency value as monitored area, place in this minute;

(4) determine that work plane belongs to production period or non-productive period;

(5) calculate energy and the frequency of per hour or the activity of every order of classes or grades at school rock noise according to the movable energy of rock noise per minute in monitored area and the frequency, whether produce in conjunction with down-hole simultaneously, calculate respectively production period or non-productive period hour or class rock noise energy and the abnormal coefficient of the frequency;

(6) choose hour or class rock noise energy and the larger desired value of the abnormal coefficient of the frequency are carried out shock hazard evaluation.

2. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: between the infield of described probe and monitored area, do not have the geology fracture area of disturbing elastic wave propagation, described geology fracture area comprises work plane, tomography and goaf.

3. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: described bolt diameter is 20mm, and described anchor pole gos deep into the length >=1.5m in coal and rock.

4. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: detection probe installs whether qualified method is to knock on other anchor poles of distance probe 5m-20m with tup; If receive all test signals of knocking, the installation qualification of popping one's head in.

5. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: the whether qualified method of detection probe sound insulation is to knock on other anchor poles of distance probe < 5m with tup; If the noise within 5m is not recorded, be arranged on probe sound insulation on anchor pole qualified.

6. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: determine that work plane belongs to production period or non-productive period, passes through W _pparameter to working surface production during and non-productive period divide, W _pfor the numerical value of output, advance rate, coal-winning machine available machine time or power consumption, W _tbe the average of this parameter in certain working time unit, work as W _p>aW _ttime this period be production period, a is 0.2.

7. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: the abnormal coefficient k of the production period class rock noise frequency _azwdesign formulas be:

$k_{\mathrm{azw}}=|\frac{N_{\mathrm{azw}}-\stackrel{\&OverBar;}{N_{\mathrm{azw}}}*100\%}{N_{\mathrm{azw}}}*100\%|$

In formula:

N _azw: production period, the rock noise frequency value of current class;

the average of front 10 class's of production rock noise frequencys.

8. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: the abnormal coefficient k of production period class rock noise energy _ezwdesign formulas be:

$k_{\mathrm{ezw}}=|\frac{E_{\mathrm{ezw}}-\stackrel{\&OverBar;}{E_{\mathrm{ezw}}}*100\%}{E_{\mathrm{ezw}}}*100\%|$

In formula:

E _ezw: production period, the rock noise energy value of current class;

the average of front 10 class's of production rock noise energy.

9. press method for early warning the roadway bump based on monitoring ground sound according to claim 1, it is characterized in that: divide four danger classess according to abnormal coefficient, without dangerous: <0.25, weak dangerous: 0.25-1.0, moderate risk: 1.0-2.0 is dangerous by force: >2.0.